CANAAN, Maine — A forefather of Maine’s environmental conservation movement has passed away. Clinton “Bill” Townsend died early Thursday while sleeping at his home on Nelson Hill Road, according to his daughter Eliza Townsend. He was 89 years old.

Townsend, a longtime lawyer in Skowhegan, was best known for his work with many of Maine’s most influential environmental advocacy organizations and regulatory authorities, such as the Natural Resources Council of Maine, The Nature Conservancy, the former Land Use Regulatory Commission and Land for Maine’s Future.

From 1990 through 1994, he served as one of three United States commissioners to the North Atlantic Salmon Conservation Organization, appointed by President George H. W. Bush.

During his life, Townsend was recognized for his environmental advocacy by several groups, having received the River Network’s “River Hero Award,” the Gulf of Maine Council’s Environment Visionary Award and Down East Magazine’s Environmental Award.

Eliza Townsend, a former state legislator and commissioner of the state Department of Conservation, recalled her father as a kind and funny man who was especially passionate about preserving open spaces, and public access to those spaces, in Maine.

“His passion was fishing,” she said. “Fish and water — running water mostly. [His environmental conservation work] was about making sure Maine people had access to the land that they loved.”

In a statement, Sen. Angus King said Bill Townsend was “a dear friend and one of my most treasured mentors” who did much for Maine.

“He was a man of enormous intellect and even greater character who fought tirelessly to deliver justice for people across Maine and who worked unceasingly to preserve and protect Maine lands and resources for the enjoyment of future generations,” King wrote. “I will miss Bill tremendously but am grateful for his many years of friendship and counsel, and more importantly, for all that he has done on behalf of our beloved state.”

In a statement posted Friday on the Natural Resources Council of Maine website, Executive Director Lisa Pohlmann wrote that Maine is better off today than it was 60 years ago, in large part because of conservation efforts promoted and spearheaded by Townsend.

“At the time, Maine’s rivers were terribly polluted, with minimal levels of dissolved oxygen essential to support fish and other life. Bill worked along the Kennebec River and its condition was never far from his mind,” Pohlmann wrote. “He leaves behind many, many friends and a Maine that is far healthier and more protected than the one he first encountered when [his wife] Louise and he moved their young family to the state in the 1950s.”

Townsend became a “giant” in Maine’s conservation movement, Pohlmann added. With his legal skills, he helped lead the campaign to create the Allagash Wilderness Waterway, she said, and helped to prevent construction of a dam at Big Amberjackmockamus Falls and the proposed Basin Mills Dam in the lower Penobscot watershed.

“Each of these structures would have caused irreparable harm to Maine’s fisheries,” she wrote.

U.S. Rep. Chellie Pingree said Friday that Townsend represents the “most effective and passionate” of many advocates in Maine who have vigorously pushed for the conservation and restoration of the state’s natural resources.

“His passionate leadership for Maine’s rivers and environment has left an indelible mark throughout the state, both in the organizations he helped lead and the causes he advocated for,” Pingree wrote. “I truly appreciate and admire his contributions to our great state.”

Townsend was a lawyer in Skowhegan since 1958, for most of that time with the firm Perkins, Townsend, Shay & Talbot.

He graduated from Harvard College in 1949 and from Harvard Law School in 1953. He served two stints as prosecuting attorney for Somerset County, in 1963-64 and again in 1967-68, during which he tried a total of more than 100 jury cases.

Townsend’s involvement with environmental conservation groups and campaigns lasted for more than 50 years. He was president of the Natural Resources Council of Maine from 1965 through 1971 and chairman of the Maine Chapter of The Nature Conservancy in 1972 and 1973. He was appointed to the former Maine Land Use Regulation Commission during his chairmanship of the Nature Conservancy, and he served on the Land for Maine’s Future board from 1988 through 1998.

He is a past president of Maine Rivers and served on its board of directors and, at various points, also served on the boards of the Atlantic Salmon Federation, the Maine Council of the Atlantic Salmon Federation and Somerset Woods Trustees.

Townsend is survived by his wife, Louise, son Ben, daughters Eliza and Meneely, and his grandchildren, according to Pohlmann.